JPH05236394A - Television receiver - Google Patents

Abstract

PURPOSE:To automatically and accurately turn off the power source and to suppress unnecessary power consumption when a video signal input is ceased by providing a control circuit which turns off the power circuit of a receiver main body when a video presence/absence detecting circuit detects video absence. CONSTITUTION:The video presence/absence detecting circuit 8 is arranged behind an input switching circuit 3 and detects whether or not there is the video signal to turn off the power circuit 9 of the receiver main body through the control circuit 7 when detecting the absence of the video signal. When the video presence/absence detecting circuit 8 detects the ceasing of the video signal input in either use mode wherein the video signal is inputted from an external input terminal 1 or use mode wherein a broadcast video signal is inputted through a tuner circuit 2, the power circuit 9 of the receiver main body is automatically turned off through the control circuit 7 to prevent the power source from being left ON forgetfully.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention is applicable to, for example, VTRs and LDs.
The present invention relates to a television receiver having an input terminal for a video signal from an external AV device such as.

[0002]

2. Description of the Related Art FIG. 2 is a block diagram showing a schematic configuration of a conventional television receiver of this type. In FIG. 2, reference numeral 1 denotes an external input terminal for a video signal from an external AV device, which is normally one. The above is provided. A tuner circuit 2 selects a broadcast video signal received by the antenna 10. An input switching circuit 3 switches between the video signal from the external input terminal 1 and the video signal from the tuner circuit 2.

A video processing circuit 4 processes the video signal from the switching circuit 3 and sends the video signal to the synchronizing circuit 5 and the picture tube 6. A control circuit 7 outputs a switching command signal to the input switching circuit 3. Reference numeral 9 is a power supply circuit of the receiver main body.

Next, the operation of the above configuration will be described.
Either the video signal from the external AV device or the video signal from the tuner circuit 2 input to the external input terminal 1 is input to the video processing circuit 4 via the input switching circuit 3. A video signal is sent from the video processing circuit 4 to the synchronizing circuit 5 and the picture tube 6, and a picture is displayed on the picture tube 6 while being controlled by the synchronizing circuit 5.

By the way, an external AV is connected to the external input terminal 1.
When a video signal is input from the device and the video is displayed on the picture tube 6, when the video signal from the external AV device is interrupted due to, for example, the end of the VTR playback or the power being turned off, The screen of the picture tube 6 becomes dark and indistinguishable from the state in which the power supply circuit 9 of the main body of the picture receiver is turned off. Therefore, for example, even if the reproduction of the VTR is finished or the power is turned off, the screen of the picture tube 6 is dark, so that it may be left as it is, that is, with the power supply circuit 9 of the receiver main body turned on. is there.

As a means for preventing forgetting to turn off the power source, when a video signal is no longer input in a conventional usage mode in which a video signal is input from the external input terminal 1, a picture is displayed on a dark screen of the picture tube 6. Characters are displayed, or display media such as light emitting diodes are used for display.

Even when an image is displayed on the picture tube 6 through the tuner circuit 2, the power supply circuit 9 is turned on unless the user turns off the power supply circuit 9 when the image disappears due to the end of broadcasting. It is in a state as it is.

[0008]

Since the conventional television receiver is constructed as described above, when there is no input of the video signal from the outside in the use mode of the input from the external input terminal, that problem occurs. Is displayed to call attention to the user, the user must eventually turn off the power supply circuit or switch channels to manually operate the power supply. It was inevitable to waste money. Further, even when the broadcast signal is displayed through the tuner circuit, there is a problem that it is easy to forget to turn off the power after the broadcast ends.

The present invention has been made in order to solve the above-mentioned problems, and the video signal can be input regardless of whether the video signal is input from the outside or the broadcast video signal is used. An object of the present invention is to provide a television receiver capable of automatically and surely turning off the power when the power is consumed and suppressing unnecessary power consumption.

[0010]

A television receiver according to the present invention is provided in a subsequent stage of an input switching circuit for switching a video signal from an external input terminal for inputting a video signal from an external device and a video signal from a tuner circuit. It is arranged to include an image presence / absence detection circuit for detecting the presence / absence of an input image signal, and a control circuit for turning off the power supply circuit of the receiver main body when the image absence / presence detection circuit detects the absence of an image. And

Further, the control circuit has a function of sending a command signal for switching the input switching circuit to the tuner circuit side when the video presence / absence detection circuit detects the absence of a video when the video signal is inputted from the external input terminal. Is desirable.

Further, it is more preferable that the control circuit has a delay timer function of turning off the power supply circuit of the receiver main body after a predetermined time when the absence / presence of the image is detected by the image presence / absence detection circuit.

[0013]

According to the present invention, in any of the usage mode in which the video signal is input from the external input terminal through the input switching circuit and the usage mode in which the broadcast video signal is input through the tuner circuit, When the video signal detection circuit detects that there is no video signal input, the power supply circuit of the receiver main body will be automatically turned off via the control circuit, and it is possible to prevent forgetting to turn off the power supply. Is.

In particular, when a video signal is detected by the video presence / absence detection circuit at the time of inputting a video signal from the external input terminal, the input switching circuit is switched to the tuner circuit side by a command signal from the control circuit, so that the broadcast time zone As long as it is, the broadcast image is displayed on the screen of the picture tube, and it is possible to avoid a state in which the screen is dark and indistinguishable from the power-off state.

Further, when the absence / presence of a picture is detected by the picture presence / absence detection circuit, the power supply circuit of the receiver main body is turned off after a predetermined time without immediately turning off the power supply circuit. It is possible to avoid the inconvenience that the power is cut off.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 is a block diagram showing a schematic configuration of a television receiver according to an embodiment of the present invention. In FIG. 1, 1 to 7, 9 and 10 are the same as those in the conventional example shown in FIG. Are denoted by the same reference numerals and detailed description thereof will be omitted.

In FIG. 1, reference numeral 8 is an image presence / absence detection circuit,
The control circuit 7 is arranged in the subsequent stage of the input switching circuit 3 to detect the presence or absence of an input video signal and detect the absence of video.
The power supply circuit 9 of the receiver main body is turned off via the.

Next, the operation of the above configuration will be described.
Since the operation of processing the input video signal by the video processing circuit 4 and displaying the video on the screen of the picture tube 6 is the same as the conventional one, a detailed description thereof will be omitted.

In the above operation, the video signal sent from the input switching circuit 3 is the video presence / absence detection circuit 8
The presence or absence of the video signal is detected by the synchronizing signal, and the information signal indicating the presence or absence thereof is input to the control circuit 7. In the control circuit 7, when the input switching circuit 3 is switched to the side of the external input terminal 1 and receives an information signal indicating no image, an off command signal is output to the power supply circuit 9 and the power supply circuit 9 outputs the command signal. Is automatically turned off. Further, even when the input switching circuit 3 is switched to the tuner circuit 2 side, when an information signal without video is received,
An off command signal is output to the power supply circuit 9 to automatically turn off the power supply circuit 9. This prevents forgetting to turn off the power supply circuit 9.

It should be noted that in the above embodiment, the information signal of no image is received regardless of whether the input switching circuit 3 is switched to the external input terminal 1 side or the tuner circuit 2 side. When the input switching circuit 3 is switched to the external input terminal 1 side, the control circuit 7 controls the power supply circuit 9 to be turned off. The input switching circuit 3 is switched to the tuner circuit 2 side by a command signal from the power source circuit 9 when a video-less information signal is received after switching to the tuner circuit 2 side.
By controlling so that the power is turned off, it is possible to prevent unnecessary power-off operation and prevent forgetting to turn off the power when the broadcast time period ends.

Further, in the above embodiment, the image presence / absence detection circuit 8 is described to be turned off immediately when the image presence / absence detection circuit 8 detects the absence of an image.
By providing the control circuit 7 with a delay timer function of turning off the power supply circuit 9 after a predetermined time has elapsed after detecting no video, for example, in the middle of watching a video signal from a VTR, It is possible to avoid the inconvenience that the power supply circuit 9 is unnecessarily turned off when the cassette tape is replaced.

Further, with respect to the control circuit 7,
It is also possible for the user to set the user selection contents by an operation circuit (not shown). For example, regardless of whether it is an external input video signal or a broadcast video signal from the tuner circuit 2, if no video is detected, the first state in which the power supply circuit 9 is turned off and the external input video signal If no video is detected while inputting, the broadcast video signal is switched to the input from the tuner circuit 2, and if no video is detected when the broadcast video signal is input, the power supply circuit 9 is turned off. The second state such as “can be set” may be arbitrarily selectable by the user.

Furthermore, when an external video signal is input from the external input terminal 1 when the power supply circuit 9 of the receiver main body is off, it is more convenient to have a function of automatically turning on the power supply circuit 9. Is.

[0024]

As described above, according to the present invention, in any of the usage mode in which the video signal is input from the external input terminal and the usage mode in which the broadcast video signal is input through the tuner circuit, Since the power supply circuit of the receiver main body can be automatically turned off by detecting that the video signal is no longer input, external A such as VTR or LD
When the video signal is not being input while the video signal from the V device is being watched, and the screen is dark, leave the power on and broadcast it while watching the broadcast video signal. It is possible to suppress the waste of power consumption due to forgetting to turn off the power when the process ends. Also,
All you have to do is add a video presence detection circuit to the conventional circuit,
It can be constructed at low cost.

In particular, if the power supply circuit is turned off after a predetermined period of time when no image is detected, it is possible to avoid the inconvenience that the power is turned off unnecessarily when the cassette tape is replaced in the VTR. However, it has a practical effect of preventing forgetting to turn off the power supply.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a television receiver according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a conventional television receiver.

[Explanation of symbols]

 1 External Input Terminal 2 Tuner Circuit 3 Input Switching Circuit 4 Image Processing Circuit 6 Picture Tube 7 Control Circuit 8 Image Presence Detection Circuit 9 Power Supply Circuit

Claims (3)

[Claims] 1. An external input terminal for inputting a video signal from an external device, a tuner circuit, an input switching circuit for switching a video signal from the external input terminal and a video signal from the tuner circuit, and a video processing circuit, In a television receiver provided with a picture tube for displaying a video signal, a video presence / absence detection circuit arranged after the input switching circuit to detect the presence / absence of an input video signal, and an image presence / absence detection circuit A television receiver comprising a control circuit for turning off the power supply circuit of the main body of the receiver when the absence is detected. 2. The control circuit has a function of transmitting a command signal for switching the input switching circuit to the tuner circuit side when a video absence detection circuit detects a video absence at the time of inputting a video signal from an external input terminal. The television receiver of claim 1, wherein 3. The television receiver according to claim 1, wherein the control circuit has a delay timer function of turning off the power supply circuit of the receiver main body after a predetermined time when the absence / presence of the image is detected by the image presence / absence detection circuit. ..