JPH1141531A - Test pattern signal generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of parts and to enable a user to easily set an RF channel by providing an on-screen IC for generating vertically correlated video signals and outputting them to a television receiver. SOLUTION: When an instruction signal is inputted from a microcomputer 4, an on-screen IC 2 generates a test pattern composed of vertically correlated images. An RF converter 3 converts this test pattern to the frequency of the idle channel of the television receiver and outputs it to the television receiver. The on-screen IC 2 outputs the test pattern through initial setting with a PAL system synchronizing signal as a reference. When an NTSC system television receiver is connected, the flow of a picture is longitudinally generated in the displayed test pattern. Since the picture does not flow in the horizontal direction, it can be used as a test pattern for RF channel setting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a case where a plurality of television receivers of different television broadcasting systems are connected.
The present invention relates to a test pattern signal generator capable of generating a test pattern signal for adjusting an F output frequency.

[0002]

2. Description of the Related Art Conventionally, in a recording / reproducing apparatus such as a video tape recorder, an RF converter for converting a video signal into a specific frequency signal receivable by the television receiver is used for reproducing the video signal by the television receiver. On the other hand, a television receiver displays a video signal by tuning an internal receiver to a frequency signal converted by an RF converter.

By the way, there are various television broadcasting systems, for example, the NTSC system in Japan and the PAL system in Europe are mainly used, and different horizontal scanning lines and frame frequencies are set in each broadcasting system. ing. For example, a signal of the NTSC system is composed of a video signal of 30 frames / sec having 525 horizontal scanning lines, and a signal of the PAL system is composed of a video signal of 25 frames / sec having 625 horizontal scanning lines. Have been.

[0004] In Japan where the NTSC system is adopted, the first channel or the second channel is provided as a vacant channel that does not receive television broadcasting depending on the receiving area.
It is generally used as a reproduction channel of a video signal converted by a converter (hereinafter, referred to as “RF channel”). Therefore, when an NTSC video tape recorder is connected to a television receiver for the first time,
The user switches the switch on the back to any channel that does not receive television broadcasts,
Channel settings can be made.

On the other hand, in the PAL system, a specific channel of a television receiver is not prepared as an RF channel. And the user is 3 in the UHF band.
Any available channel around six channels can be used as a reproduction channel of the video signal from the video tape recorder. Therefore, when a PAL video tape recorder is connected to a television receiver for the first time, the user adjusts the video signal conversion frequency of the RF converter to the frequency of an empty channel around 36 channels in the UHF band of the television receiver. The empty channel will be used as an RF channel.

For this purpose, a dedicated transmitter for displaying a test pattern for adjustment is provided in the RF converter of the video tape recorder, and is turned on by turning on a switch of the transmitter provided on the rear surface. After adjusting the video signal conversion frequency of the RF converter so that the test pattern displayed on the television receiver is clearly displayed, the RF channel is set by turning off the transmitter. It can be carried out.

The same applies to a video tape recorder compatible with a plurality of broadcasting systems which can be connected to a television receiver of a broadcasting system different from the NTSC system and the PAL system. A transmitter for displaying the pattern is provided, and the RF converter uses the test pattern for adjustment not only when a PAL television receiver is connected but also when an NTSC television receiver is connected. The RF channel is set by adjusting the video signal conversion frequency of to an empty channel around 36 channels in the UHF band.

[0008]

As described above, in a video tape recorder compatible with a plurality of broadcasting systems, R
A transmitter had to be provided in the RF converter to set the F channel, and a switch was needed to activate the transmitter. Therefore, providing each dedicated component has led to an increase in the cost of the video tape recorder.

In addition, it is very troublesome to operate a switch on the back after connecting a video tape recorder to a television receiver and installing the video tape recorder in accordance with a use environment, resulting in poor operability.

Further, in a video tape recorder corresponding to a plurality of broadcasting systems, even if the video tape recorder outputs a test pattern signal, there is a large deviation in the setting of the RF channel, so that nothing is displayed on the television receiver. Instead, the user was confused.

[0011]

In order to solve the above-mentioned problems, a video signal of a recording medium recorded based on any one of a plurality of television broadcasting systems is transmitted via an RF converter to an available channel of a television receiver. In displaying, the test pattern signal generator for adjusting the RF output frequency according to the present invention, which generates a test pattern for adjusting the frequency to the empty channel by the RF converter, outputs a video signal having a vertical correlation. Happened
An on-screen IC for outputting the video signal to the television receiver;
Adjusting means for adjusting an output frequency, and further, when outputting the video signal from the on-screen IC to the television receiver, outputting recognition information to a display means. It is characterized by the following.

[0012]

FIG. 1 is a block diagram showing a test pattern signal generator according to the present invention. Here, 1 is a video signal processing circuit for processing a video signal in a video tape recorder, 2 is a video signal input from the video signal processing circuit, and adds on-screen information to the input video signal and a menu screen. Or, an on-screen IC for generating a test pattern for RF channel adjustment, 3 is an on-screen IC
An RF converter for converting a video signal output from 2 into a frequency of a vacant channel of the television receiver and outputting the converted signal to the television receiver; 4, a microcomputer for sending various control signals to the on-screen IC; And display means for displaying, during a period in which the on-screen IC is generating the test pattern, a user to recognize that a test pattern signal is being generated.

As shown in FIG. 1, the test pattern signal generator according to the present invention does not have a dedicated transmitter in the RF converter, and adjusts the RF channel regardless of the connection of any broadcasting television receiver. The on-screen IC generates a test pattern signal that can be performed, and a display that allows a user to recognize the occurrence of the test pattern signal is generated on the video tape recorder while the test pattern signal is being generated. Is what you do.

First, the operation of the on-screen IC 2 will be described. The on-screen IC 2 outputs a video signal by adding on-screen character information to the video signal input from the video signal processing circuit 1 and outputs the video signal (hereinafter referred to as “external synchronization mode”). There is a mode for outputting a menu screen or a test pattern for RF channel adjustment without outputting a signal (hereinafter, referred to as “internal synchronization mode”).

In the external synchronization mode, whether the input video signal is an NTSC video signal or a PAL video signal is input to the on-screen IC 2, the on-screen IC 2 is input. By adding character information at a predetermined timing based on a synchronization signal of a video signal, on-screen character information can be reproduced.

On the other hand, in the internal synchronization mode for outputting the menu screen, the video signal from the video signal processing circuit 1 is cut off in the on-screen IC 2, so that the broadcast system identification signal input from the microcomputer 4 is used. The menu screen is output at a predetermined timing based on either the NTSC or PAL synchronization signal generated inside the on-screen IC 2.

However, when the video tape recorder is connected to the television receiver for the first time, the on-screen IC
2 is set so as to output the menu screen at a predetermined timing based on the synchronization signal of the PAL system.

Therefore, when a PAL television receiver is connected, the synchronization signals match, so that R
The menu screen can be displayed on the television receiver by adjusting the F channel. However, when the NTSC television receiver is connected, a shift occurs in the synchronization signal. Cannot be displayed.

FIG. 2 shows an example of a test pattern for adjusting the RF channel generated by the on-screen IC 2. When an instruction signal for generating a test pattern is input from the microcomputer 4, the on-screen IC 2 generates a test pattern composed of vertically correlated images as shown in FIG. Is converted into the frequency of a vacant channel of the television receiver, and then output to the television receiver.

At this time, it is assumed that the on-screen IC 2 outputs the test pattern based on a PAL synchronization signal by initial setting. Therefore, when a PAL television receiver is connected, it is natural that a test pattern is displayed by adjusting the RF channel. However, even when an NTSC television receiver is connected, the test pattern is displayed. The test pattern is displayed because it is a video pattern having a vertical correlation.

That is, in the test pattern shown in FIG. 2, when an NTSC television receiver is connected, a screen flow occurs in the vertical direction, but a screen flow occurs in the horizontal direction. Therefore, it can be used as a test pattern for setting the RF channel without any problem.

The microcomputer 4 is an on-screen IC
At the same time as outputting an instruction signal for generating a test pattern to the display unit 2, a control signal for indicating that the test pattern is being generated is output to the display unit 5. FIG. 3 shows the microcomputer 4
5 shows a display example of the display means 5 based on the control signal from the control unit 5. The user is required to output the test pattern signal from the video tape recorder even if the test pattern is not displayed on the television receiver, for example, by displaying the character "_OUT" as shown in FIG. Can be confirmed.

FIG. 4 is a flowchart showing a procedure for setting the RF channel by the user when the video tape recorder is connected to the television receiver for the first time. In a state where the power switch is off and the video tape is not inserted (step 10), if the user keeps pressing the stop button for more than 5 seconds (step 11), the RF is transmitted from the on-screen IC.
The test pattern for channel adjustment is output (step 12), and at the same time, the character "_OUT" is displayed on the display means. In this state, the test pattern is not always displayed on the television receiver, and the user continuously changes the video signal conversion frequency adjustment knob of the RF converter provided in the video tape recorder (step (1)). 13) Display the test pattern and make fine adjustments to make it appear sharper.

When the adjustment is completed so that the test pattern is clearly projected on the television receiver,
The user presses the stop button again (step 14), turns off the display of the test pattern and the display of the character "_OUT", and ends the RF channel setting operation.

In this embodiment, the on-screen IC 2
Has shown an example in which the test pattern signal is output with reference to a PAL synchronization signal, but the same applies to the case where the test pattern signal is output with reference to an NTSC synchronization signal. It can be displayed on the machine. Further, in this embodiment, an example in which the user uses the stop button as the instruction button for displaying the test pattern has been described, but it goes without saying that another button can be used instead.

[0026]

As described above, in the test pattern signal generator according to the present invention, since the on-screen IC 2 outputs the test pattern signal for RF channel adjustment,
There is no need to provide a transmitter in the converter, and there is no need to provide a dedicated changeover switch on the rear surface, so that the production cost can be reduced.

Since there is no switch for outputting a test pattern on the back of the video tape recorder, the RF channel can be easily set even after the video tape recorder is installed.

Furthermore, since the user can confirm whether or not the test pattern signal is being generated at present by the display means 5, the user can set the RF channel without any confusion.

[Brief description of the drawings]

FIG. 1 is a block diagram of a test pattern signal generator according to an embodiment of the present invention.

FIG. 2 is an example of an RF channel adjustment test pattern generated by the test pattern signal generator according to the embodiment of the present invention.

FIG. 3 is a display example of a display unit of the test pattern signal generator according to the embodiment of the present invention.

FIG. 4 is a flowchart showing a procedure for setting an RF channel in a video tape recorder including a test pattern signal generator according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Video signal processing circuit 2 ... On-screen IC 3 ... RF converter 4 ... Microcomputer 5 ... Display means

Claims (2)

[Claims] When displaying a video signal of a recording medium recorded based on any one of a plurality of television broadcasting systems on an empty channel of a television receiver via an RF converter, the video signal is transmitted to the empty channel by the RF converter. For generating an RF output frequency adjustment test pattern signal for generating a test pattern for adjusting the frequency of a video signal, generating a video signal having a vertical correlation, and outputting the video signal to the television receiver. On-screen IC
And an adjusting means for adjusting an RF output frequency while watching an image based on the video signal. 2. The RF output frequency adjustment test pattern signal generator according to claim 1, wherein the identification information is output to display means when the video signal is output from the on-screen IC to the television receiver. A test pattern signal generator for adjusting an RF output frequency.