JPH04103282A - Wide aspect identification signal insertion circuit - Google Patents

Abstract

PURPOSE:To discriminate the aspect ratio of an input signal automatically by superimposing a wide aspect identification signal onto a color signal when the aspect ratio of the input video signal is either 4:3 or 16:9 and outputting the superimposed signal onto a wide aspect ratio television receiver. CONSTITUTION:A luminance signal (a) is inputted to a wide aspect television receiver 5 and a horizontal synchronizing signal separator section 2, and the horizontal synchronizing signal separator section 2 separates a horizontal synchronizing signal (b) when the aspect ratio of the input video signal is 16:9 and a wide aspect identification signal generating section 3 generates a wide aspect intermediate frequency signal (g) synchronously with the horizontal synchronizing signal (b) and comprising a pulse whose polarity is inverted for each one horizontal scanning period. Then the identification signal (g) and a color signal (h) are mixed by a mixer circuit 4, and a superimposing signal (i) of the both is inputted to a wide aspect television receiver 5. Thus, the receiver 5 detects the wide aspect identification signal (g) from the signal (i). Thus, the aspect ratio of the input signal is automatically discriminated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a wide aspect identification signal insertion circuit for inserting a wide aspect identification signal for determining an aspect ratio into a color signal.

Conventional technology In recent years, as display devices have become wider, wide aspect television receivers with an aspect ratio of 16:9,
There are strong prospects for the appearance of devices such as wide-aspect projectors and the start of wide-aspect television broadcasting.

When wide aspect ratio conversion is implemented, when inputting a video signal from a video tape recorder (hereinafter referred to as VTR) to a wide aspect television receiver (hereinafter referred to as TV), the input signal is wide on the TV side. It is necessary to determine whether the video signal has an aspect ratio of 4, 3 or 16 with a manual switch.
You need to judge and choose from 20.

SUMMARY OF THE INVENTION However, in the conventional method of selecting and switching the aspect ratio, the switching must be performed using a manual switch, which is time-consuming and troublesome.

SUMMARY OF THE INVENTION The present invention is intended to solve the above problem, and aims to provide a wide aspect identification signal insertion circuit for automatically determining the aspect ratio of an input video signal on the TV side.

Means for Solving the Problems In order to solve the above problems, the wide aspect identification signal insertion circuit of the present invention has an input video signal with an aspect ratio of 4+3.
, 16:9, a horizontal synchronizing signal separation unit that separates a horizontal synchronizing signal from an input luminance signal, and a wide aspect identification signal consisting of a pulse whose polarity is inverted every horizontal scanning period from the horizontal synchronizing signal. The wide-aspect identification signal generation unit generates a wide-aspect identification signal, and a mixing circuit mixes the wide-aspect identification signal and an input color signal and outputs a signal in which the wide-aspect identification signal is superimposed on the color signal.

Effect: With the above configuration, the wide aspect identification signal is superimposed on the color signal and output, and by checking this wide aspect identification signal on the TV side, the aspect ratio of the input signal can be automatically determined. It becomes possible.

Example Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a block diagram of a wide aspect identification signal insertion circuit in one embodiment of the present invention.

The wide aspect identification signal insertion circuit l of the present invention separates the horizontal synchronization signal from the input luminance signal a using a wide aspect discrimination signal input from a VTR controller, for example, when the aspect ratio of the input video signal is 16=9. a wide aspect identification signal generator 3 that generates a wide aspect identification signal g consisting of a pulse whose polarity is inverted every horizontal scanning period from the horizontal synchronizing signal; The mixing circuit 4 mixes input color signals and outputs a signal i, which is a wide aspect identification signal superimposed on the color signal, to a wide aspect television receiver 5.

FIG. 2 shows a specific circuit diagram of the wide aspect identification signal generating section 3.

The wide aspect identification signal generation section 3 performs a logical product of the output signal C of the 1/2 frequency divider 6, which divides the frequency of the horizontal synchronization signal by 1/2, and the horizontal synchronization signal C. AND circuit 7.172 An inverter 8 that inverts the output signal C of the frequency divider 6, a NAND circuit 9 that obtains an inverted output of the AND of the output signal e of the inverter 8 and the horizontal synchronization signal S, and the output signal d of the AND circuit 7. and an emitter follower lO which inputs the output signal f of the NAND circuit 9 via a capacitor and a resistor, and outputs a wide aspect identification signal g.

The operation of the wide aspect identification signal insertion circuit 1 of the present invention will be described below with reference to the waveform diagram of FIG.

The luminance signal a shown in FIG. As shown in the figure, the horizontal synchronizing signal is separated and input to the wide aspect identification signal generating section 3.

This horizontal synchronization signal is input to the 172 frequency divider 6, AND circuit 7, and NAND circuit 9 of the wide aspect identification signal generation section 3, and is divided into 172 by the 172 frequency divider 6 as shown in FIG. , the AND circuit 7 outputs a positive pulse synchronized with the horizontal synchronizing signal every two horizontal scanning periods, and as shown in FIG. 3, the NAND circuit 9 outputs the output signal of the AND circuit 7 every two horizontal scanning periods. d and one horizontal scanning period, a negative pulse synchronized with the horizontal synchronizing signal S is output, and a wide aspect identification signal g consisting of a pulse whose polarity is inverted every l horizontal scanning period synchronized with the horizontal synchronizing signal is output from the emitter follower 10. Output.

The wide aspect identification signal g and the color signal are mixed in a mixing circuit 4, and a signal i in which the wide aspect identification signal is superimposed on the color signal is input to the wide aspect television receiver 5.

Therefore, by detecting the wide aspect identification signal g from the signal i, the wide aspect television receiver 5 can automatically determine the aspect of the input signal, thereby saving time and effort.

Note that in this embodiment, the aspect ratio of the input video signal is 1.
Although the wide aspect identification signal g is inserted when the aspect ratio is 6:9, it goes without saying that it may be inserted when the aspect ratio is 4:3.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, when the aspect ratio of an input video signal is either 4:3 or 16:9, a wide aspect identification signal is superimposed on a color signal to produce a wide aspect television. By outputting the signal to the receiver, the wide aspect television receiver can automatically determine the aspect ratio of the input signal, thereby saving time and effort.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a wide aspect identification signal insertion circuit according to an embodiment of the present invention, FIG. 2 is a circuit diagram of a wide aspect identification signal generation section of the wide aspect identification signal insertion circuit, and FIG. 3 is a block diagram of the wide aspect identification signal insertion circuit according to an embodiment of the present invention. FIG. 3 is a waveform diagram of main parts of the identification signal insertion circuit. 1... Wide aspect identification signal insertion circuit, 2...
Horizontal synchronization signal separation section, 3... Wide aspect identification signal generation section, 4... Mixing circuit, 5... Wide aspect television receiver, a... Brightness signal, b... Horizontal synchronization signal, g...Wide aspect identification signal, h...
...Color signal, i... A signal in which a wide aspect identification signal or a wide aspect identification signal is superimposed on the color signal.

Claims (1)

[Claims] 1. A horizontal synchronization signal separation unit that separates a horizontal synchronization signal from an input luminance signal when the aspect ratio of the input video signal is either 4:3 or 16:9; A wide aspect identification signal generation unit that generates a wide aspect identification signal consisting of pulses with inverted polarity, mixes the wide aspect identification signal and an input color signal, and outputs a signal in which the wide aspect identification signal is superimposed on the color signal. A wide aspect identification signal insertion circuit consisting of a mixing circuit and a wide aspect identification signal insertion circuit.