JPH03163973A - Television receiver - Google Patents

Abstract

PURPOSE:To eliminate the trouble to operate a switch manually in the absence of a signal in each mode by repeating mode switching automatically up to a mode wherein an input signal is present if there is no input signal in a switched mode. CONSTITUTION:When a mode changeover switch attached to a television receiver main body or remote controller is pressed, a microcomputer 10 sends control signals to a video signal switching circuit 8 and an audio signal switching circuit 14 respectively to switch a current mode to a next mode. Then an image signal decision circuit 17 and an audio signal decision circuit 18 decide whether there is an input signal in the switched mode and if it is decided that there is no input signal, the microcomputer 10 sends a switching control signal for switching to the next mode to a video signal switching circuit 8 and an audio signal switching circuit 14 to perform the switching to the next mode.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a television receiver having a plurality of external inputs, and in particular to a television receiver having a plurality of external inputs, and in particular, a television receiver that automatically switches inputs depending on the presence or absence of an input signal. This invention relates to an input switching device.

[Prior Art] FIG. 3 is a schematic diagram showing the flow of video signals and audio signals in a conventional television receiver.

In the figure, (l) is an antenna, (2) is a tuner,
(3) is a video intermediate frequency amplification circuit, (4) is a video detection circuit, (5) is a 4.5 MHz audio detection circuit, (6) is an audio intermediate frequency amplification circuit, and (7) is an FM detection circuit. The television broadcast signal received by the antenna (1) is tuned by the tuner (2), passes through the video intermediate frequency amplification circuit (3), and the video signal is converted into a video detection signal by the video detection circuit (4). Therefore, the audio signal is 4.5 MHz
An audio signal is generated by the audio detection circuit (5), the audio intermediate frequency amplification circuit (6), and the FM detection circuit (7).

(8) is a video signal switching circuit, (l4) is an audio signal switching circuit, (98), (9B) ... (9N) are external input devices, (10) is a microcomputer, and the video detection circuit (
4) The video detection signal output from the external input device (9A
), (9B) ... (9N) are selected by the microcomputer (lO) in the video signal switching circuit (8), while the audio signal output from the FM detection circuit (7) and the external input device (9＾) , (9B) ・・
- The signal from (9N) is selected by the microcomputer (lO) in the audio signal switching circuit (l4).

(11) is a video amplification circuit, (12) is a color signal reproduction circuit,
(13) is a CRT, which constitutes a system for outputting the signal selected by the video signal switching circuit (8) to the CRT (13). (l5) is a low frequency amplification circuit, and (16) is a speaker, which constitutes a system for outputting the audio signal selected by the audio signal switching circuit (14) to the speaker (16).

Next, the operation of the above configuration will be explained.

Video signal switching circuit (8) and audio signal switching circuit (14)
) is controlled by a microcomputer (lO), and both video and audio signals are input to external input devices (98), (9B)...
・The input signal from (9N) is selected and the CRT (13
) and output to the subica (16).

Here, there are roughly the following two types of methods for inputting signals to the microcomputer (IO).

One has as many switches as there are input signals,
One method is to directly select the desired input signal, and the other is a method that consists of one or two switches, and the input signals are sequentially switched each time the switch is pressed. The state of each input signal is called a mode.

[Problem to be Solved by the Invention] Since the conventional television receiver is configured as described above, when using the number of switches corresponding to the number of input signals, there is a drawback that the signal selection operation tends to be confusing. There is. In addition, if the mode is changed sequentially using only one or two switches, the mode switching operation becomes easier, but it is difficult to automatically switch to the next mode when there is no input signal. Therefore, there is a problem in that the number of switch operations increases, including the number of modes in which there is no input signal.

This invention was made to solve the above-mentioned problems, and it is possible to reduce the number of operations by automating mode switching when there is no signal in a sequential mode switching method that requires a small number of switches. The purpose is to provide a television receiver that can.

[Means for Solving the Problems] The television receiver according to the present invention is configured to determine the presence or absence of an input signal each time the mode is switched, and to automatically repeat mode switching until the determination result becomes YES. It is characterized by

[Operation] According to the present invention, when switching modes sequentially, the presence or absence of an input signal is determined each time the mode is switched, and if there is no signal, the mode is automatically switched to the next mode until a signal is present. By repeating the steps above, it is possible to omit manual switch operations for mode switching when there is no signal.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described based on the drawings.

FIG. 1 is a schematic configuration diagram showing the flow of video signals and audio signals of a television receiver according to an embodiment of the present invention, in which (17) is a video signal determination circuit;
Reference numeral 8) denotes an audio signal determination circuit, which determines the presence or absence of a signal at the time of mode switching and inputs the determination result to the microcomputer (10). Since the rest of the structure is the same as that of the conventional example shown in FIG. 3, the same reference numerals are given to the corresponding parts and detailed explanation thereof will be omitted.

Next, among the operations of the above configuration, the operation when the mode changeover switch is pressed will be explained with reference to the flowchart shown in FIG.

When the mode selection switch attached to the television receiver body or remote control is pressed (step 19), control signals are sent from the microcomputer (10) to the video signal switching circuit (8) and the audio signal switching circuit (14), respectively. hand,
A changeover from the current mode to the next mode takes place (step 20).

Next, the presence or absence of an input signal in the switched mode is determined by a video signal determination circuit (l7) and an audio signal determination circuit (l8).
) (step 21), and if it is determined that there is no signal, the microcomputer (10) sends a control signal for switching to the next mode to the video signal switching circuit (8) and the audio signal switching circuit (14), Repeat 20 or less operations.

In addition, if it is determined in step 21 that there is a signal, both the video signal and the audio signal are sent directly to the next stage circuit, that is, the video amplification circuit (11) and the low frequency amplification circuit (11).
5) (step 22).

In the above embodiments, a television receiver having a plurality of external inputs has been described, but a monitor display or other multi-input switching device may be used, and the same effects as in the above embodiments can be achieved.

[Effects of the Invention] As described above, according to the present invention, in the sequential mode switching method, if there is no input signal in the switched mode, the mode switching is automatically repeated until the mode with the input signal is present. This eliminates the need to manually operate the switch when there is no signal, and significantly improves the operability of mode switching.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing the flow of video and audio signals in a television receiver according to an embodiment of the present invention, FIG. 2 is a flowchart of mode switching operation, and FIG. 3 is a conventional television receiver. FIG. 2 is a schematic configuration diagram showing the flow of video signals and audio signals. (8)...Video signal switching circuit, (9A), (9B
)...(9N)...External input device, (10)...
...Microcomputer, (l3)...CRT, (14)...
Audio signal switching circuit, (16)...Speaker, (17)
...Audio signal determination circuit, (18)...Video signal determination circuit. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] (1) In a television receiver having means for sequentially switching between multiple input signals, there is a signal determination circuit that determines the presence or absence of an input signal when switching from the current input state to the next input state, and a signal determination circuit that determines the presence or absence of an input signal when switching from the current input state to the next input state, and 1. A television receiver comprising: means for automatically repeating switching of input states until it is determined that an input signal is present.