JPS61111079A - Television receiver - Google Patents

Abstract

PURPOSE:To prohibit the appearing of the ugly image of full of noise when the TV broadcast ends or when a VTR reproducing terminates by reading the picture information stored in the picture memory beforehand to visually display it when the receiving video signal is no longer received. CONSTITUTION:While the video signal is being supplied to a video signal detecting circuit 10 from a video detecting circuit 3 or an external image input terminal 8, the video signal to be displayed is detected by the detecting circuit 10. A switching circuit 11 is connected to a terminal (a), and the receiving video signal is supplied to a CRT (cathode ray tube) 7, and the image is visually displayed on the screen of the CRT. In case the video signal is no longer supplied due to the finishing of the TV broadcasting or terminating of reproducing of an external image equipment of such as VTR, the switching circuit 11 is turned to terminal (b) based on the detection output of the video signal detecting circuit 10. In this case, the picture information read from the picture memory 12 and converted to analogue information by a D-A converter 13, is supplied to the CRT7 via an image circuit 6, and is displayed on the screen of the CRT.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a television receiver that can display an appropriate image even when there is no received television signal.

BACKGROUND TECHNOLOGY Normally, general television receivers receive television broadcast radio waves and project and display the contents of the television video signal on a CRT screen. When the program ran out or there was no program to watch, the only option was to turn off the power and turn off the screen.

Purpose The present invention has been made in view of the above points, and provides a television set/receiver capable of projecting and displaying an appropriate image even when the received television video signal is no longer available. It is.

<Example> The following will explain the embodiments shown in the drawings.

In the drawing, 1 is a tuner, 2 is an intermediate frequency circuit, 3 is a video detection circuit, 4 is a synchronization separation circuit, 5 is a deflection circuit, 6 is a video circuit, 7 is a cathode ray tube (CRT), 8 is an external video input terminal, 9 is a television/external/input selector switch, and these individual structures are not particularly different from those normally used in general television receivers. When receiving normal television broadcasting, the input changeover switch 9 is connected to the terminal (2) as shown, and the television video signal obtained from the video detection circuit 3 is supplied to the synchronization separation circuit 4 and the video circuit 6. VT to unilateral sexual part video input terminal 8
Only when an external video device such as R or a video disc player is connected and the selector of the changeover switch 9 is switched to the terminal ■ side, an external video signal from the external video device is sent to the sync separation circuit 4 instead of the television video signal. and is supplied to the video circuit 6.

In this embodiment, a general television receiver comprising the above-mentioned components further includes a video signal detection circuit 10 that detects the presence or absence of a video signal, and a switching circuit 11 that performs a signal switching operation based on the detection output of this detection circuit 10. , an image memory 12 that digitally stores image information for at least one frame, and an image memory 12 that converts the digital information read from the image memo I)-12 into analog information D-
A converter 13, a rewrite switch 14 that rewrites the information stored in the image memory 12 when desired, and an external video signal input from the external video input terminal 8 via this switch 14, which converts it into digital information. It is constructed by adding an A-D converter 15.

In the above television receiver, the switch 9 is connected from the video detection circuit 3 or the external video input terminal 8.
While the video signal is being supplied to the video signal detection circuit 10 via the video signal detection circuit 10, this video signal is detected by the detection circuit 10, and at this time, the switching circuit 11 is connected to the terminal ■ as shown in the figure.
The received video signal is connected to the CR via the video circuit 6.
The video signal is supplied to T7, and as a result, a television broadcast or video from an external video device is projected and displayed on the CRT screen.

However, when the video signal disappears at the end of a television broadcast or when the playback operation of an external video device, such as a VTR, stops, the switching circuit 11 switches to the terminal ■ side based on the detection output of the video signal detection circuit 10. At this time, the image information read from the image memory 12 and converted into analog information by the DA converter 13 is supplied to the CRT 7 via the video circuit 6 and displayed on the CRT screen.

In this way, in this embodiment, the video signal detection circuit 10 constantly detects the presence or absence of a received video signal, and when the video signal disappears, the switching circuit 11 automatically performs the switching operation, and the image information read out from the image memory 12 at this time. CRT
It is displayed on the screen.

If the switching circuit 11 is configured to be able to switch not only the detection output of the video signal detection circuit 10 but also directly by manual operation, the information stored in advance in the image memory 12 can be projected and displayed on the CRT screen as desired. becomes possible.

Note that in the above embodiment, the rewriting switch 14 is normally in the off state, and only when it is desired to rewrite the image information stored in the image memory 12, the rewriting switch 14 is in the on state and the external video equipment is connected to the external video input terminal 8 as desired. Image information is inputted, passed through an A-D converter 15, converted into digital information, and then supplied to the image memory 12, where it can be rewritten with new image information.

Effects> As described above, according to the television receiver of the present invention, when there is no received video signal, the image information stored in the image memory in advance is read out and this image information is automatically displayed. Therefore, noisy and unsightly images are not displayed even when a television broadcast ends or when VTR playback stops.

[Brief explanation of drawings]

The drawing is a block diagram of one embodiment of the invention.

Claims (1)

[Claims] 1. An image memory that stores image information for at least one frame, a video signal detection means that detects the presence or absence of a received video signal, and a video signal detection means that detects the received video signal and the image information read from the image memory. and a switching means for supplying the switching video circuit based on the detection output of the means, so that when the received video signal disappears, image information stored in advance in the image memory can be automatically projected and displayed. A television receiver featuring: