JP2506718B2 - Television receiver - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color television receiver, and an image having a screen aspect ratio (aspect ratio) different from that of a conventional television image signal (3: 4). The present invention relates to a television receiver capable of receiving a signal.

2. Description of the Related Art FIG. 3a shows a video signal having an aspect ratio (3: 4) of a conventional television signal on a display having a conventional aspect ratio. In the contents of software of video tapes and video discs that are currently on the market, such as movies,
In order to convey all the information of the image (in the movie, the aspect ratio is not 4: 3, but is wide such as 2.15: 1,
If the entire surface is displayed with an aspect ratio of 4: 3, the left and right information will be lost.) As shown in Fig. 3b, many blanks (black strips) 1 are put on the top and bottom without changing the movie size. . A movie-sized software that has a wide display with a different aspect ratio than that of a conventional display (eg, an aspect ratio
When projected at 16: 9), in addition to the top and bottom blanking 1 as shown in Fig. 5a, the left and right blanking areas (in the figure, the left and right blanking areas are left from 4: 3 to 16: 9 region)
2 increases. If the screen is expanded in the horizontal direction and the vertical direction by the same ratio in order to make the screen wider and more flexible, the blanking regions 1 and 2 become invisible as shown in FIG. 5b. Horizontal. Vertical stretching can be accommodated by each of the prior art line memory applications and vertical amplitude adjustment functions.

Problems to be Solved by the Invention However, in the conventional technique, when the movie size software is input, it is necessary to change the horizontal and vertical amplitudes (length on the screen) from the current state. This requires that the person watching the display see the contents of the image and make adjustments.

The present invention provides a television receiver which automates this adjustment and displays a screen by providing blanking areas on the left and right in the case of normal video software and displays the screen in full in the case of movie size software. With the goal.

Means for Solving the Problems In order to solve the above problems, that is, in order to automatically adjust the horizontal and vertical lengths, a vertical blanking width is detected and blanking is performed for a certain period or longer. If the period continues, the length of the horizontal amplitude is changed according to the length of the period.

Effect In the present invention, when blanking is included in the vertical direction in the software contents of the image, by detecting the length of the blanking period and automatically changing the vertical / horizontal amplitude from the period length, With a wide display having an aspect ratio different from that of conventional displays, it is possible to provide a follow-up screen without holding the viewer's hand.

Embodiment An embodiment of the present invention is shown in FIG. A waveform for explaining the principle is shown in FIG.

First, a description will be given with reference to FIG. FIG. 2 (a) is a video signal waveform in the case of normal software, and FIG. 2 (b) is a video signal waveform in the case of movie size software. In the case of FIG. 2 (a), the blanking period is am sec, and in the case of FIG. 2 (b), the blanking period is bm sec.

When the blanking width τ is τ ≦ τ _O m sec, it is a normal state, and when τ> τ _O m sec, the width of the horizontal amplitude and the vertical amplitude is changed. Now, when τ _O = a is set, FIG. 2A shows a normal state. If b> a, one vertical scanning period is 16.7
The period of the video signal from m field (1 field) to vertical is (16.7-a) m sec in FIG. 2 (a) and (16.7-b) m sec in FIG. 2 (b), and the video amplitude is (16.7-b)
Since it is as small as /(16.7-a), Fig. 5 (b)
Vertical and horizontal amplitude (16.7-a)
It must be multiplied by /(16.7-b). As a result, in the case of normal video software, a screen with left and right blanking areas as shown in Fig. 4 is displayed, and in the case of software of video size, it is displayed as a full-screen image as shown in Fig. 5b. can do.

In FIG. 1, the television signal input from the video input terminal 11 is an analog / digital conversion circuit (A / D).
The converter) 12 converts the digital signal. A / D at this time
The clock of the converter 12 is generated by the clock generation circuit 13. Further, the clock generating circuit 13 generates a write clock (W-CK) and a read clock (R-CK) for the line memory 17 and line memory 18 for storing the output from the A / D converter 12. This line memory 17,18
Then, for movie size software, write clock W-
CK and read clock R-CK use the same clock,
In the case of normal size software, the frequency of the read clock R-CK is set higher than that of the write clock W-CK. By doing so, the movie size is set to fill the horizontal direction, and the vertical direction swings the vertical amplitude circuit 15 in the sync separation circuit 14 to the vertical direction of the wide display, as shown in FIG. 5 (b). Next, in the case of normal software, the read clock R-CK is faster than the write clock W-CK, so it contracts in the horizontal direction and the vertical amplitude circuit 15 contracts in the vertical direction as shown in FIG. The line memory 17 and the line memory 18 are read by the line memory 18 when the line memory 17 is writing.
When 17 is being read, the line memory 18 is being written. The switching circuit 19 operates so as to switch the outputs of the line memory 17 and the line memory 18 by the alternating line pulse from the sync separation circuit 14, and the output is converted into an analog signal by a digital / analog conversion circuit (D / A converter) 20. After being converted, the signal is processed and amplified by the video amplifier circuit 21 and the CRT22
Is projected in. Another vertical blanking width detection circuit 16 is connected to the video input terminal 11. Here, the vertical blanking width for movie size software 16: 9 is b _O m sec, the vertical blanking width for normal video software is a _O m sec, and the CRT22 has an aspect ratio of 16: 9. To do. The vertical blanking width detection circuit 16 detects this vertical blanking pulse width, and when the video signal is a movie size (16: 9)
The control output of the vertical blanking width detection circuit 16 is output to the vertical amplitude circuit 15 so as to extend the vertical amplitude to 4/3,
By outputting a control signal to the clock generation circuit 13 so that the read clock R-CK has the same frequency as the write clock W-CK, the image can be displayed as shown in FIG. 5 (b). In the case of normal software, the vertical amplitude is 3/4 that of the above condition.
In other words, the read clock R-CK of the clock generation circuit 13 is set to 4/3 times the write clock W-CK in order to bring the state into the normal state and the horizontal amplitude to 3/4 from the above state. As a result, the image can be displayed as shown in FIG. Note that the vertical blanking period is detected by obtaining a reference signal and determining whether the vertical blanking period of the video signal is longer or shorter than the pulse width of the signal, or after A / D conversion. It can be reached by counting the clocks in the vertical blanking period.

EFFECTS OF THE INVENTION According to the present invention, in a CRT having a screen wider than a normal aspect ratio, in the case of movie size software, it can be enjoyed on a wide screen without vertical blanking. In the case of, the image can be displayed without the signals of up, down, left, and right, and the extra space can be displayed without missing the screen such as the information of other CHs (the so-called picture-in-picture displays the sub-screen as the main screen. It can be displayed. In this way, when movie size software is input, it automatically becomes a follow-up screen, and when using normal software, not only can you see the image, but you can also enjoy other information.

[Brief description of drawings]

FIG. 1 is a block diagram of a television receiver according to an embodiment of the present invention, FIG. 2 (a) is a vertical sync video sync signal waveform diagram of normal video software, and FIG. 2 (b) is a movie size software. Vertical rate video / synchronization signal waveform diagram, Fig. 3 (a) is a front view of a television receiver having a conventional aspect ratio CRT and normal software is projected, and Fig. 3 (b) is a conventional diagram. Front view of a movie size software projected on a television receiver having a CRT with an aspect ratio of
Fig. 4 is a front view of a television receiver having a wide aspect ratio CRT, in which normal size software is detected, and Fig. 5 (a) is a television receiver having a wide aspect ratio CRT. Front view of the size software projected, Figure 5 (b) is a wide aspect ratio CR
It is a front view of the state which projected the movie size software on the television receiver which has T without vertical and horizontal blanking width. 11 …… Video input terminal, 12 …… A / D converter, 13 …… Clock generator, 14 …… Sync separation circuit, 15 …… Vertical amplitude circuit, 16 …… Vertical blanking width detection circuit, 17 …… Line memory, 18 …… Line memory, 19 …… Switching circuit, 20 ……
D / A converter, 21 …… Video amplification circuit, 22 …… CRT (wide display).

Claims (1)

(57) [Claims] 1. A detecting means for detecting a vertical blanking period of a television video signal, and a television for varying a horizontal amplitude and a vertical amplitude of the television video signal according to a time width of the detected vertical blanking period. Receiver.